(1) Field of the Invention
The present invention relates to a label joining method and a label joining apparatus for separating from an release paper a label having a surface on which a two-dimensional barcode, a QR code (registered trademark), a character, a symbol, or the like is printed, and joining the label to a work piece.
(2) Description of the Related Art
To separate a label from an release paper when joining the label, there is known a method in which the release paper holding the label joined onto a top surface is folded back and reversed at a front end of an edge member while the release paper is being fed forward, and the label to be separated from the release paper by such folding-back is suction-held by a suction head from a printed surface of the label, while air is being blown to an adhesive surface of the label (see Japanese Laid-Open Patent Publication No. 10-264915).
In the above-mentioned method, the suction head is disposed in a standby state in front of the edge member such that a suction surface is laid horizontal. The label is fed forward from a folded-back position of the release paper while blowing air from below to the label fed forward from the folded-back position of the release paper at the front end of the edge member. At this time, the label trying to droop downward due to its own weight is lifted up by the air. The suction head sucks the label through a suction surface directed downward with part of a rear end of the label being held onto the release paper. Due to such a phenomenon, the label fed forward from the folded-back position of the release paper is fed forward while being vibrated or waved by the air blown from below.
In this case, when the label is moved forward, a top surface of the vibrated or waved label repeatedly hits the suction surface of the suction head on standby. Consequently, the top surface of the label is rubbed with the suction surface of the suction head. There sometimes occurs a problem that barcode information printed on the top surface of the label may be damaged by such rubbing.
Further, the adhesive surface on a bottom surface of the label is exposed to blowing air for a long period of time because air blow treatment is carried out through the entire processes of suction-holding the label. As a result, there occurs another problem that adhesion of the adhesive surface may be deteriorated.